C# design pattern for different types of files

I programming with C#.

My scenario is how handle Write/Read with different files(i.e. .xml, .txt, .csv,...).
Which design pattern is better for your opinion?

My experience for the solution:

Interfraces:

interface IFileWrite
{
    void WriteFile();
}

interface IFlieRead
{
    string ReadFile();
}

Abstract class:

class AbstractFile
{
    private string _path;
    private string _suffixFile;

    public AbstractFile(string path,string suffix)
    {
        _path = path;
        _suffixFile = suffix;
    }


    protected string Path
    {
        get { return _path; }
        set { _path = value; }
    }
    protected string SuffixFile
    {
        get { return _suffixFile; }
        set { _suffixFile = value; }
    }

}

Diffrenet files to inherit form AbstractFile and interfaces: (for example LogFile (.txt) can only write)

class LogFile : AbstractFile, IFileWrite
{

    public LogFile() : base(Environment.CurrentDirectory, ".txt")
    {

    }

    public void WriteFile()
    {
        throw new NotImplementedException();
    }
}

And finally FileManager thats knows only how to Write/Read File:

class FileManager
{
    public string GetTextFromFiles(IEnumerable<IFlieRead> aLstReadableFiles)
    {
        StringBuilder objStrBuilder = new StringBuilder();
        foreach (var objFile in aLstReadableFiles)
        {
            objStrBuilder.Append(objFile.ReadFile());
        }
        return objStrBuilder.ToString();
    }

    public void SaveTextIntoFiles(IEnumerable<IFileWrite> aLstWritableFiles)
    {
        foreach (var objFile in aLstWritableFiles)
        {
            objFile.WriteFile();
        }
    }
}